Electrical connector



Feb. 10, 1942. oma 2,272,432

ELECTRICAL commc'ron Filed Nov. 28, 1940 wvs/v TOR J. M. ROG/E AT TOPNEVPatented Feb. 10,1 2

ENT wice a ELECTRICAL CONNECTOR James M. West Orange, N. 'J assignoi' toBell Telephone Laboratories, Incorporated, New York; 1.. a'corporation'of New' York 1 I .1 Application November-i2 8,1949, serialNo. 361,524

I (or. 173-332) This invention relates to. electrical connectors I andmore particularly to connectors of the plug nickel tubes and-having aninner diameter sufilcient to permitl,the bared conductors. being andjack type for use 'withflexible conductors.

on hearing aids or similar apparatus.

In apparatus'for aiding the hearing of small receivers are positioned inthe ears of the user and it is therefore not only necessary to insuregood electrical contacts but it is also highly desirable that theflexible cords and connectors be as light and inconspicuous as possible.It is, therefore, an object of this invention to provide an electricalconnector suitable for use on such apparaus which will insuresatisfactory electrical connections and which will be light,inconspicuous and-economical to manufacture. This and other objects ofthe invention are ob tained by employing the ends of the cord conductorsreinforced by metallic tubes, as the actual terminal members of theconnector and positioning these terminals in an insulating plug shell sothat they are firmly and accurately held in position. The plug shell isprovided with a ridged portion cooperating with a corresponding openingin the apparatus with which it is associated so that the plug may beinserted in only one position thus polarizing it. Furthermore the cordis anchored in the plug sleeve by a collar on a tapered sheath placedover the covering or jacket of the flexible cord. These and otherfeatures of the invention may be more clearly understood by reference tothe attached drawing, in which:

Fig. l is a perspective view approximately to scale of a plug and cordembodying the features of the invention;

Fig. 2 is a greatly enlarged view partly in section showing this plugassociated with an earpiece for deaf sets;

Fig. 3 is a sectional view of the plug and sheath;

Fig. '4 is a plan view with one half of the plug shell removed;

Fig. 5 is a view of the various parts ready for assembly; and

Fig. 6 is an end view of the plug.

Referring more particularly to Figs. 3 to 5, there is disclosed-aflexible cord comprising a pair of silk or plastic insulated conductorsill-4U enclosed in a covering or jacket ll of rubber or plasticinsulation which is preferably extruded thereabout while the conductorsare maintained in parallel relation. Alternatively this covering may bea covering of textile threads. The insulation from the ends of theconductors is rethe deaf moved and they are threaded through thin walledthreaded therethrough. The tubeswith the enclosed conductors are .thenplaced in a suitable .flxture and. subjected to sufficient-pressure toform the flat terminal members I2'-|2. These terminal members areprovided with struck-up portions or projections l3l3 and I l-l4 torespectively aid in securing the members in an insulating shell and tocooperate with contacting springs in associated apparatus in a manner tobe described later herein.

In order .to prevent undue strain on individual conductors and toincrease the life of the cord, the end of the cord is provided with atapered protecting sheath l5. This sheath is preferably formed bywrapping the end of the cord jacketwith a plastic resin tape and thenplacing it in a mold where it is subjected to heat and pressure to forma tapered sheath having a flange portion is. The plug shell consists oftwo similar members I! and I8 of suitable insulating material andprovided. with longitudinal slots I9-I9 to receive the terminal membersl2|2 and depressions 20- -20 to receive and position the projectionsl3-l3. Cavities 2l2| are provided in members I! and I8 to receive thefiangeportions it of sheath l5 thereby making it possible to anchor thecord so that undue stress will not be exerted on the individualconductors. The shell members I! and 18 are cemented or otherwisesecured together, the various parts being accurately positioned by pins22 and 23 in member I! which enter corresponding openings 24 and 25 inmember IS. The pin 23 further serves as a separator between conductorsIII-l0 thereby providing increased insulatlon. In order to polarize thedevice ridges 2626 are formed on members I I and I8 thereby providingthe plug with a semicircular projection on one edge as more clearlyshown by Fig. 6.

In Fig. 2 this plug with its cooperating contact springs is shown inconnection with the earpiece of a hearing aid. The lower housing 21 ofthe ear-piece is provided with an opening corresponding to the contourof the plug member as shown in Fig. 6 so that the plug may be insertedin only one position. A circular disc 28 of insulating material isprovided with U-shaped contact springs 29-29 secured at one end tothedisc by means of rivets 30. The free ends of these springs are formedso that when the plug is inserted the projections l4 ride over theformed end of spring 29 and are held firmly in place, the greater lengthof the plug shell being enclosed within the housing 21. In Fig. 1 theconnector is'shown substantially to scale, the length 01 theplug shellbeing approximately inch and the connecting cord being approximately byinch in size. It will be noted that while this connector is arranged toinsure perfect electrical contacts it is very light and small in sizeand is not any more conspicuous than is the ordinary cord attached toeye-glasses.

What is claimed is: I

1. A terminal member comprising a plurality 01' contact membersconsisting of thin nickel tubes threaded over the bared conductors of aconnecting cord and pressed flat, said tubesbefore being pressed havingan inner diameter only slightly larger than the diameter or the baredconductors threaded therethrough, each of said contact, members beingprovided with a plurality of crimpedprojections, which serve to anchorthe bared conductors therein.

2. In an electrical connector for flexible cords,

a plug member including an insulating shell,

verse projection crimped therein to fit into a corresponding slot insaid shell portion and with a second crimped projection adapted tocooperate with a contact spring member associated therewith, the baredends of said conductors being threaded through said tubes and anchoredtherein by said crimped portions.

3. An electrical connector for flexible cords comprising a plug memberadapted to engage contact springs 01' apparatus with which said plug isto be associated, said plug member comprising an insulating shell havinga projecting ridge on one edge only, contact members consisting ofmetallic tubes threaded'over the bared ends of said conductors andpressed flat, said contact members being provided on the same side onlywith crimped projections adapted to engage contact springs on theassociated apparatus and an opening in the housing of the associatedapparatus to receive said plug, said opening being enlarged at one sideto receive the ridge of said plug shell whereby theeplug may be insertedonly in the'position in which the projections on said contact membersengage said associated contact springs.

- JAMES M. ROGIE.

